The best experience of Moera on mobile would be with a native application. It may be written in React Native using the existing Moera client code base or from scratch with any other language and framework. In any case, it will take a lot of working hours, and I currently prefer to invest them into adding new big features that are still missing in Moera. But if anybody is ready to take this task, this would make all Moera users happy 😄
In the meantime, you may use a mobile browser with the Moera extension. The regular Moera client is usable on mobile, although not always looking good. I'll try to adapt the client for mobile where possible.
Mobile browsers that support extensions are: Firefox (tested and recommended), Kiwi, Yandex, Dolphin and maybe others.
Mobile Chrome browser, unfortunately, does not support extensions and will not in the near future.